Products> SpecGAGE3D

Inspection system for specular and reflective surfaces

Using our area type 3D sensor SpecGAGE3D, specular surfaces like
those of eyeglass lenses, head-up-displays, plastic films, decorative trims,
solar cells, hard disks, etc. can be measured quickly and very accurately
in a cost efficient manner. This product provides a tool for development
and quality assurance departments to improve the production process in order
to avoid manufacturing errors and, consequently, to minimize costs.

Measurement Principle

The new sensor is based on the principle of phase measuring
deflectometry. To calculate the local slope of a surface a fringe pattern
with a sinusoidal profile is projected onto a ground glass. A video camera
observes the reflections of this pattern via the surface under test. The
local slope of the surface can directly be calculated from the distortions
of the observed fringe pattern. The local surface curvature is simply the
first derivative of the local slope.

This technique provides crucial advantages when compared with range measuring methods
since for curvature computation the data have to be differentiated only
once. Thus, high frequency noise is much less amplified than in the case
of range data, which have to be differentiated twice.

Measurement Examples

Defect detection on automotive decorative trim parts

Measuring a progressive eyeglass lens

The local mean surface power (mean curvature) is represented on the left
side, the local astigmatism is displayed on the right.

Sensor Specifications

Measurement Principle

- Phase Measuring Stereo Deflectometry

Field of view

- 80 x 80 mm2

Measuring range

- ±18°

Measurement uncertainty

- ±0.02 dpt

Calibration

- The device is factory calibrated and can be re-calibrated by a technician
on request.